A retroactive or after-the-fact permit is a process for addressing work that was completed without the required permit. It can involve plans, inspections, corrections and evidence that would not be needed in the same way before construction.
Building departments use their own terminology, deadlines and procedures. Treat this as a practical orientation and verify the current rule with the jurisdiction that issued — or would issue — the permit.
The underlying code review may be similar, but completed work can create additional documentation and inspection issues because some conditions are no longer visible.
No. The city can require corrections or additional documentation before approving or finaling the work.